Solutions to errors in Windows 10 64bit installation of dotnetfx 3.5 (memo)

Found from the installation image: microsoft-windows-netfx3-ondemand-package.cab

For example: X:\ cn_windows_10_enterprise_x64_dvd_6846957\ sources\ sxs\ microsoft-windows-netfx3-ondemand-package.cab

Run cmd as an administrator (win+x, command prompt (administrator))

Paste the following part and enter (the red part is replaced with the path where your .cab package is located)

Dism.exe / online / add-package / packagepath:E:\ cn_windows_10_enterprise_x64_dvd_6846957\ sources\ sxs\ microsoft-windows-netfx3-ondemand-package.cab

After the above operation is completed, copy the following parts to cmd and enter

Dism.exe / online / enable-feature / featurename:NetFX3 / Source:E:\ cn_windows_10_enterprise_x64_dvd_6846957\ sources\ sxs\ microsoft-windows-netfx3-ondemand-package.cab

Description: the first run may be slow or report errors due to various reasons, never mind, finish patiently. If you report an error, restart the machine and execute it again in order, and you will basically be able to install dotnetfx3.5.